to believe especially on uncertain or tentative grounds; "Scientists supposed that large dinosaurs lived in swamps"
talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion; "We were speculating whether the President had to resign after the scandal"
invest at a risk; "I bought this house not because I want to live in it but to sell it later at a good price, so I am speculating"
charge falsely or with malicious intent; attack the good name and reputation of someone; "The journalists have defamed me!" "The article in the paper sullied my reputation"
the act of playing for stakes in the hope of winning (including the payment of a price for a chance to win a prize); "his gambling cost him a fortune"; "there was heavy play at the blackjack table"